Test-retest and Internal Consistency of the Disability of Arm, Shoulder and Hand (DASH) Outcome Measure in Assessing Functional Status among Breast Cancer Survivors with Lymphedema

Background: The Disability of Arm, Shoulder and Hand (DASH) outcome measure is a self-report questionnaire that can be used with breast cancer survivors (BCS) to measure physical, social and psychological functioning of the upper limb. The internal consistency of the DASH outcome measure has been demonstrated in BCS but there is limited psychometric support for use of the DASH with BCS with lymphedema. Purpose: The purpose of this study was to determine test-retest reliability and internal consistency for the use of the DASH among BCS with lymphedema. Methods: Following Institutional Review Board approval, test-retest reliability was evaluated as follows: participants completed the DASH outcome measure at the initial physical therapy evaluation and again 2-3 hours later by telephone interview (n=19). In order to test internal consistency of the DASH among BCS with lymphedema, a retrospective chart review of DASH scores (n=144) was conducted in a hospitalbased outpatient physical therapy facility. Coefficients reflecting internal consistency were calculated at initial evaluation (n = 144), 30 day re-evaluation (n=44) and discharge (n=59). Results: Strong test re-test reliability (ICC=0.97) and internal consistency (a=0.97, 0.92, and 0.98) were established. Conclusions: The DASH is a reliable measure of upper extremity function among BCS with lymphedema.